Solve for $x$ and $y$ using elimination. ${4x-y = 20}$ ${-3x+y = -14}$
Solution: We can eliminate $y$ by adding the equations together when the $y$ coefficients have opposite signs. Add the top and bottom equations together. ${x = 6}$ Now that you know ${x = 6}$ , plug it back into $\thinspace {4x-y = 20}\thinspace$ to find $y$ ${4}{(6)}{ - y = 20}$ $24-y = 20$ $24{-24} - y = 20{-24}$ $-y = -4$ $\dfrac{-y}{{-1}} = \dfrac{-4}{{-1}}$ ${y = 4}$ You can also plug ${x = 6}$ into $\thinspace {-3x+y = -14}\thinspace$ and get the same answer for $y$ : ${-3}{(6)}{ + y = -14}$ ${y = 4}$